1. Field of the Invention
The present invention pertains to a method of killing or arresting a gas blowout of a well using a dense gel which includes hydroxypropyl guar and a weighting agent.
2. Background
Gas blowouts sometimes occur during the drilling of a well or due to the malfunction of a well device or structure. Relatively dense liquids are usually employed during the drilling of a well and often when attempting to arrest or kill a well blowout. Drilling fluids comprising a water or oil base together with a weighting agent and a dispersant or fluid loss control material are commonly used as "kill" fluids in attempts to control a gas blowout of a well. The use of this type of material is often not very successful, depending on the pressures and velocities of the gas stream, since the counterflow of the gas stream with respect to the flow of the kill fluid into the well creates substantial turbulence and atomization of the kill fluid. The result is that the kill fluid flow cannot overcome the gas flow, is entrained with the gas flow and ejected from the well in a turbulent spray or atomized state. However, with the method of the present invention, a gas well blowout is more easily brought under control using a material which is generally readily available for oil field operations and uses, as a fundamental component, hydroxypropyl guar.
U.S. Pat. Nos. 4,708,206, issued Nov. 24, 1987, 4,817,719, issued Apr. 4, 1989, 4,819,727, issued Apr. 11, 1989, all to Jennings, Jr., and 4,899,819, issued Feb. 13, 1990 to Hazlett, et al all describe processes for shutting in a well using a solidifiable, pumpable gel mixture which includes hydroxypropyl guar gum. However, these patents do not suggest using a dense cohesive gel-like material in a method for stemming the flow of gas in a gas blowout of a well, which is an essential aspect of the present invention.